In a diesel engine (hereinafter, refer simply to as an engine) in recent years, there has been known a technique which achieves a reduction of nitrogen oxide (NOx) discharged from the engine, and a reduction of a noise and a vibration of the engine, by supplying a high-pressure, fuel to an injection in relation to each of cylinders while utilizing a common rail type fuel injection device, and electronically controlling an injection pressure, an injection timing and an injection period of the fuel from each of the injectors (refer to Patent Documents 1 and 2).